The invention relates to wire machinery, and more specifically to an "outside-in" double twist bow buncher for simultaneously twisting two sets of wires or strands and winding each set onto one of two bobbins arranged in the machine.
Machines sometimes denominated as stranders, bow stranders, twisters, double twist twister, pairing machines, double twist stranders, twinners, cablers, bunchers, and double twist bunchers have been in existence for over thirty years. Subsequently referred to as "double twist bunchers", these machines are used to combine a plurality of individual strands of wires and bunch them together by imparting a double twist to them.
Typically, the individual strands or wires are payed off a plurality of bobbins and directed to the input end at one axial end of the machine. The wires are all grouped or bunched together at a closing point prior to the entry of the machine. The wires are all grouped or bunched together at a closing point prior to the entry of the machine. The closing point remains fixed relative to the main structure of the machine. The bunched wires or strands are then introduced into one end of a bow which rotates about the longitudinal axis of the machine. It is this rotation of the bow that imparts a first twist to the bunched wires. Leaving the bow at the other end, the bunched and now single twisted wires pass over a second, exit pulley or sheave, which rotates with the bow. From this rotating sheave the bunched wire is directed over a sheave that is mounted on a cradle that is stationary in relation to the frame of the machine. A second twist is imparted to the wire between the last sheave mounted on the bow and the first sheave attached to the cradle. Additional pulleys disposed within the space defined by the rotating bow, guide the now double twisted bunched wires to the stationary bobbin supported within the machine and wound on the bobbin while being evenly distributed thereon. Depending on the machine, slightly different wire guiding system arrangements have been used.
Double twist bunchers have been extensively used in the electrical wire and cable, steel tire cord and steel rope industries for decades.
In some cases, wires or strands from an external multiple pay-off are guided into the machine, twisted and laid on a bobbin disposed inside the strander ("outside-in" machine). In other cases, multiple bobbins are arranged inside the buncher which form a multiple pay-off, and the wires or strands are drawn off the bobbins, twisted and wound onto an external bobbin ("inside-out" machine). Typical machines are illustrated in the Electrical Wire and Cable Machinery brochure, published by Ceeco Machinery Manufacturing Co., Inc., the assignee of the subject application. Other exemplary structures of existing machines are disclosed in U.S. Pat. Nos. 3,570,234 and 3,732,682.
The existing machines have used diametrically opposite double bow arrangements or counterbalanced bows. A machine which uses counter-balanced bows is manufactured, for example, by Lesmo of Milano, Italy. Although the wires or strands only pass through one of the bows, the other bow is generally provided only to balance the wire-carrying or operative bow. Aside from the dynamic balancing of the system, the non-operative bow has not, up to now, been used for any other function or purpose.
Existing double twist bunchers have generally performed satisfactorily and have produced the desired product. However, each such machine has always introduced or removed the wires or strands through only one axial end of the machine.
Also, all "outside-in" machines have always wound wire onto a single bobbin disposed inside the machine. Because all wires and strands have always been introduced through only one axial end of the machine, these wires could not be distributed onto two separate bobbins since the wires or strands are immediately all twisted together when introduced into the machine.
Therefore, in order to increase production and wind additional bobbins it has been necessary to utilize a plurality of such double twist bunchers. This, of course, has entailed additional expense, and additional floor space. Since each machine is self-contained and capable of operating independently, drive components and controls must correspondingly be multiplied. Existing double twist bunchers have not heretofore shared drives or controls.